/*
 * Copyright (c) 2013. wyouflf (wyouflf@gmail.com)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.zvezda.disply.utils;

import java.util.concurrent.ConcurrentHashMap;

/**
 * Author: wyouflf Date: 13-8-1 Time: 上午11:25
 */
public class KeyExpiryMap<K, V> extends ConcurrentHashMap<K, Long>
{
	
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	
	private static final int DEFAULT_CONCURRENCY_LEVEL = 16;
	
	public KeyExpiryMap(int initialCapacity, float loadFactor, int concurrencyLevel)
	{
		super(initialCapacity, loadFactor, concurrencyLevel);
	}
	
	public KeyExpiryMap(int initialCapacity, float loadFactor)
	{
		super(initialCapacity, loadFactor, DEFAULT_CONCURRENCY_LEVEL);
	}
	
	public KeyExpiryMap(int initialCapacity)
	{
		super(initialCapacity);
	}
	
	public KeyExpiryMap()
	{
		super();
	}
	
	@Override
	public synchronized Long get(Object key)
	{
		if (this.containsKey(key))
		{
			return super.get(key);
		}
		else
		{
			return null;
		}
	}
	
	@Override
	public synchronized Long put(K key, Long expiryTimestamp)
	{
		if (this.containsKey(key))
		{
			this.remove(key);
		}
		return super.put(key, expiryTimestamp);
	}
	
	@Override
	public synchronized boolean containsKey(Object key)
	{
		boolean result = false;
		if (super.containsKey(key))
		{
			if (System.currentTimeMillis() < super.get(key))
			{
				result = true;
			}
			else
			{
				this.remove(key);
			}
		}
		return result;
	}
	
	@Override
	public synchronized Long remove(Object key)
	{
		return super.remove(key);
	}
	
	@Override
	public synchronized void clear()
	{
		super.clear();
	}
}
